требует ссылку на Windows Script Host Object Model

Sub kk()
Dim fso As FileSystemObject, f As File

Set fso = CreateObject( "Scripting.FileSystemObject" )

If Not fso.FolderExists( "c:\md" ) Then
fso.CreateFolder  "c:\md" 
End If

For Each f In fso.GetFolder( "d:\md" ).Files
f.Copy  "c:\md\"  & f.Name, True  'overwrite
Next

Set fso = Nothing

End Sub